Clutch and brake control system



Sept. 7, 1943. w p BQLDT 2,328,606

CLUTCH AND BRAKE CONTROL SYSTEM Filed April 2, 1942 4 Sheets-Sheet 1FIG.I.

TOR.H BRAKE W.F. BOLD-T INVENTOR ATTORNEY Sept. 7, 1943. w. F. BOLDT I II CLUTCH AND BRAKE CONTROL SYSTEM Filed April 2, 1942 4 SheetsSheet 2 7mag l6 20\ r 193+ V I 9 26 l 2| INVENTOR W .BOLDT u I w Sept. 7, 1943. wE BOLDT I 2,328,606

CLUTCH AND BRAKE CONTROL SYSTEM Filed April 2, 1942 4 Sheets-Sheet 5FIGS. 7 6| EQV4 INVENTOR .F BOLDT Sept. 7, 1943.

W. F. BOLDT CLUTCH AND BRAKE CONTROL SYSTEM Filed April 2, 1942 4SEeets-Sheet 4C ATTORNEY Patented Sept 7, 1943 CLUTCH AND BRAKE CONTROLSYSTEM Werner F. Boldt, Clayton, Mo., assignor to Wagner ElectricCorporation, St. Louis, Mo.I a corporation Delaware Application April 2,1942, Serial No. 437,325

15 Claims. My invention relates to control systems and more particularlyto a control system for clutches and brakes whereby a vehicle may besteered.

One of the objects of my-invention is to provide an improved clutch andbrake control system for a vehicle in which the steering thereof isaccomplished by first disconnecting the driven member on .one side ofthe vehlcle and then subsequently applying a brake thereto toprevent orretard its movement.

Another and more; specific object of my invenadapted to beconnected tothe storage tank I and are controlled bysuitable hand-operated valvemechanism generally indicated by the numeral 5 andembodylng two separatevalves enclosed in a single casing 6. This casing is connected tothestorage tank by a conduit 1 and to the power cylinders 3 and 4 by meansof con- .ciuits 8 and 9, respectively.

tion is to provide an improved control system for cle such as a militarytank and to so arrange said control system that it can beoperated fromtwo separate places in the vehicle.

Still another object of my invention is to provide a fluid pressureactuated control system for the clutches and brakes or a vehicle whichwill be so arranged that either of two clutches can be disengaged atwill and upon said disengagement the brakingsystem will automatically beso conditioned that only the proper. brake can be applied to assist insteering the vehicle.

' Other objects of my invention will become apparent from the followingdescription taken in connection with .the accompanying drawingsin' whichFigure 1 is a schematic view of a clutch and brake control systemembodying my invention; Figure 2 is a' sectional view of the clutchcontrolling valves; Figure 3 is a sectional view.

taken on the line 3-3 of Figure 2; Figure 4 is a sectional view 01 the.control valve mechanism (or the brakes, said view being taken on theline of Figure 5; Figure 5 is a sectional view taken on the line 5-5 ofFigured; Figure 6 is steering and braking a track laying type of vehi-The construction of the valve mechanism is shown in detail in Figures 2and 3. The casing 6 is provided with a through-bore in which ispositioned rotatable valve elements II and I2 held in afrial abuttingrelation by the plugs l3 and I4 closing the ends of the bore. The valveelement Ii, which controls the left-hand clutch actuating power.cylinder 4, is provided with a shaft portion l5 which extends throughplug i3 and carries a control handle i6. Similarly, the

valve element |2 has a shaft portion l1 extend- "which conduit ingthrough plug l4 and carries the handle I8. The conduit I leading fromthe storage tank communicates with a passage IS in the wall of thecasing, said passage communicating with spaced ports 2|) and 2| enteringthe bore, the former for association with the valve element II and thelatter for association with valve element l2. The bore l0 opposite port20 has a port 22 to power cylinder 4. A port 23 is opposite port 2| andthis port is connected to conduit 8 leading to the power cylinder 3. p 7

As best shown in Figure 3, each valve element has a cross-passage 24 andaninterconnecting branch passage 25 at right angles thereto. Whenhandles l6 and i8 are in their vertical positions, each cross-passage 24will communicate a sectional view taken on the line 6--6- of Figure '4;Flgures'i, 8, 9, and 10 are various sectional views showing details,said views being taken on lines 'i-'|, 8'-8, 99, |i|li, respectively, ofFigure4; and Figures 11 and l2.are sectional views similar to Figures 7and 8 but showing the valve elements and the control shaft indifferent-positions.

Referring first to Figure the fluid pressure employed in theco'ntrolsystem is preferably compressed air although other fluids may beemclutch for disconnecting the right-hand track with an atmospheric port26 in the valve casing. When handles l6 and i8 are in their verticalpositions the valve elements will -be-inthe positions shown in vFigure3. Under these conditions both power cylinder 3 and 4 will be'incommunication with the atmosphere and the storage tank will be cut oil.If handle I8 should be swung in a clockwise direction, as viewed inFigure 3, to the position where ports 2| and 23 are placed incommunication with eachother by way of passage 24, th 11 the powercylinder 3 will be pioyed. This compressed air is stored in tanli afterbeing compressed by a compressor 2. .The

01' the'tank (not shown) from the source of power or engine is operatedby a' powercylinder 3 and the clutch for disengaging the left-hand trackfrom the source of power is controlled by a power. cylinder 4. Bothpower cylinders are operated and the right-hand clutch disengaged. Asimilar movement of handle |6wil1 cause the storage tank to be connectedto the power cylinlinder 4 and the left-hand clutch disengaged. II

handle," should be movedin'a counter-0100b wise direction (todottedposition in Figure 1) in order to cause passage 25 to no longercommuni- Gate, with port 23,- then the power cylinder 3 9 is connectedwhich leads to the handles can be manipulated by the driver of the tankwho sits in the'lower part thereof.

In a track laying tank or like vehicle there is also associated with thetrack a brake whereby the track can be held from moving. Vihn thedriving power of the track'is disconnected as by disengaging the clutch,the tank can be caused to make a short turn by braking the track whichis no longer driven from the engine. By holding the track stationary,the tank will pivot on this track and make an extremely short turn. Theturning angle may be varied by wholly or partially releasing the brake.In thecontrol system shown, the brake for the right-hand track isadapted to be applied by a power cylinder 21 and the brake for theleft-hand track is adapted to be applied by a power cylinder 28. Thesepower cylinders are operated by fluid pressure from the storage tank Iand to control them there is provided a master valve 29 of well-knownconstruction, said valve being controlled by a treadle 30 convenient tothe driver of the tank. A conduit 31 connects this master valve to thetank and a conduit 32 and branch conduits 33 and 34 lead from the valveto the power cylinders 21 and 28.

Between conduit 32 and branch conduits 33 and 34 leading to the powercylinders, I have provided a special control valve mechanism 35 which isadapted to automatically selectthe power cylinder to be actuated and thebrake thereof applied corresponding to the clutch which is disengaged.

Referring now to Figures 4 to 12, inclusive, which disclose details ofthe control valve mechanisrrr 35, said valve mechanism is embodied in acam 48. The cams are so arranged with respect to each other that whenthe shaftis in its normal or inoperative position, cam 39 will holdvalve 52 open and permit closing of valve 54 and cam 49 will hold valveelement 53 open and permit closing of valve element 55. It is thus seenthat under these conditions chamber 46, which communicates with thefoot-operated master valve '29, will be in constant communication withchambers 42 and 43 and since these chambers are in communication withthe power cylinders 21 and I 28, respectively, said power cylinders willbe in communication with valve 29 so that if said valve is operated topermit fluid under pressure to flow to conduit 32, the power cylinderswill be simultaneously operated. The normal position of the shaft andthe condition of the valve elements are shown in Figures 4 to 8.

As best shown in Figures 4, 5, and 6, the casing 36 is formed with anextension portion 6| provided with a cylinder 62 which is at rightangles to bore 31 and'slightly above the axis of said bore. Within thiscylinder is a double-headed piston 63, the central portion ofwhichreceives the end of a lever 64 which is connected intermediate itsends to the end of shaft 38. The left-hand end of cylinder 62 (as viewedin Figures 4 and 6) is casing 36 which has a bore 31 in which is mounteda shaft 38 having spaced cams 39' and 419. The

central part of the shaft between the dam is provided with a packing 4|which divides the bore into chambers 42 and 43 with cam 39 in chamber 42and cam 40 in chamber 43. The chamber 42 has a port 44 to which isconnected conduit 33 leading to the right power cylinder21 and chamber43 has a port 45 to which is connected conduit 34 leading to the leftpower cylinder 28.

On opposite sides of bore 31 are chambers 46 I and 41, chamber 46 beingconnected to conduit 32 leading from the master control valve 29 andchamber 41 being connected to an exhaust conduit 41' opening toatmosphere. A passage 48 ,connects chamber 46 to chamber 42 and apassage 49 connects said chamber 46 to chamber 43. Also, a passage 50connects chamber 41 to chamber 42 and a passage 5| connects said chamber41 i The passages 48 and 50 are in connected to a conduit 65 whichcommunicates with the previously referred to conduit 9 leading to thepower cylinder 4 for actuating the lefthand clutch. The right end ofcylinder 62 is connected to a branch conduit 66 which communicates withthe previously referred to 'conduit 8' leading to the power cylinder 3for actuating the right-hand clutch. By means of this structure it isseen that when fluid under pressure is establi'shed in the powercylinder 4 only the piston will be moved to the right and thereby rotateshaft 38 in a clockwise direction as viewed in Figure 6. When fluidpressure is established in the power cylinder 3, piston 63 will be movedto the left and will cause a counter-clockwise rotation of shaft 38, asviewed in Figure 6. In order that piston 63 may be biased to a centralposition when no fluid pressure is acting on either end of piston 63,there are provided spring plungers 61 and 68 to act upon opposite sidesof the lower end of lever 64. The ends of the plungers abut against acentral stop 69 when the piston and shaft are in their centralpositions. This central position is the normal position of the shaft asis shown in Figures 4 to 8. When the piston is moved to the right, thespring-pressed plunger 61 will be moved and act to return the piston toits central position and when the piston is moved to the left, thespring-pressed plunger 68 will he moved and act 1 to return the pistonto its central position.

56. The valve elements 52 and 54 have fluted stems, 51 and 58 whichproject into chamber 42' and are adapted to cooperate with the oppositesides of cam 39 on shaft 38. In a like manner the valve elements 53andare provided with fluted stems 59 and 66 which project into chamber43 and cooperate with the opposite sides of.

Referring now to the operation of the control controlling handles are intheir positions shown, both clutche will be in engagement. Under theseconditions, the parts of the control valve mechanism 35 will be in thepositions shown in Figures 4 to 10. If the footoperated valve 29 isactuated by the treadle, both brakes can be applied since the valveelements 52 and 53 are held open and the valve elements 54 and 55 are intheir-wclosed position. If the brakes are not applied and it is desiredto employ the brakes to assist in making a left-hand turn, the left-handhandle 16 will be pulled rearwardly, thereby connecting the powercylinder 4 to the source of pressure. This will disengage the left-handclutch. Simultaneously with the disengagement of the left-hand clutch,the fluid under pressure admitted to conduit 3 will also be effective tomove piston 83 to the right from its central position, as,shown inFigures 4 and 6'. The movement of this piston will now cause clockwiserotation of shaft 38, as viewed in Figure 6, thereby so moving cams 33and 40 that the valve element 52 will be closed and valve element 54opened without any change in the condition of the valve elements 53 and55, that is, the valve element 53 remains open and the valve element 54remains closed. The condition of all the valve elements 52, 53, 54, and55 is shown in Figures 11 and 12 after the shaft 38 is rotated in aclockwise direction as viewed in Figures 6, '7, and 8. If thetreadle-co'ntrolled valve 29 is now opened to 'connect conduit 32 to thesource of pressure, only the power cylinder 28 will be operated,thereelement 52 has been closed. It is thus seen-that with thedisengagement of the left-hand clutch and the application of theleft-hand brake, thetrack on that side of the tank will beheldstationary and the tank can pivot about this track and make the requiredturn. Release of valve 29 will release the brakes and a return of handlel6 will permit re-engagement of the clutch.

If it is desired to employ the brakes to assist in steering to theright, the right-hand handle I8 is pulled rearwardly, therebydisengaging the right-hand clutch. The fluid pressure admitted toconduit 8 will also be effective to move piston 63 to the left and causea counter-clockwise rota- .tion of shaft 38 as viewed in Figures 6, 7,and 8. Cams 39 and 40 will now be so rotated that the valve element 53will be closed and valve element 55 opened and valve element 52continued to be held open and valve element 54 continued to be heldclosed. When valve 29 is now opened,

tral position and under these conditions the cams will beagainpositioned as shown in Figures 4 to 8 where both valve elements 52and 53 will be open and both valve elements 54 and 55 closed. Thus thebrake which has not been applied will be applied by'air pressure sincethe valve shutting it off has been opened.

If both brakes should be applied when it is desired to disengage theclutch to assist insteering, then when the clutch is disengaged andpiston 63 is moved, the brake on the side of the vehicle opposite thedisengaged clutch will be automatically released. Thus, for example, ifthe righthand clutch .is disengaged when both brakes are in appliedcondition, piston 63 will be moved to the left. This will cause acounter-clockwise rotation at the shaft (as viewed in Figures 6, 7, and8) and result in cam 40 permitting the closing of valve element 53 andthe opening of valve element 55. This will now place the ower cylinder2a of th left-hand brake in communica-.

, tion with atmosphere and cause release of the brake. 'If the left-handclutch had been disengaged when the brakes were applied, then, ofcourse, the right-hand brake would have been released in an obviousmanner since the valve element 52 would be closed and the valve element54 would be opened.

If it should be desired to disengage both clutches simultaneously; bothhandles will be pulled rearwardly. This, of course, will result in theestablishment of equal pressures on opposite ends of piston 63 andconsequently the piston will not be .moved., Under these conditions bothbrakes can be applied since valve elements 52 and 53 will remain openand valve elements 54 and 55 will remain closed.

From the foregoing it is seen that there is provided a control systemfor the clutches and brakes 15 of a track vehicle, such as a tank, whichwill permit the operator to properly control the clutches and brakes toaccomplish a desired steering of the vehicle. Both brakes can be,applied at any time when the clutches are engaged. When the 20right-hand clutch is disehgaged, only the rightthe" brakes were appliedbefore or after the disengagement of the clutch. If the left-hand clutchis disengaged, only the left-hand brake can be applied regardless ofwhether the brakes were applied prior to or after the disengagement ofsaid clutch. If both clutches are disengaged, both brakes can be appliedin the same manner as though both clutches were engaged. f) In tankoperation, the driver in the presently constructed tanks does all thedriving under all conditions and he receives his instructions from thecommanding g-iiicer in the turret who transmits his desires tr thedriver by means of signals through his feet such as tapping the driveron the back. The driver thus executes the orders and moves the tank inthe direction desired. Under certain conditions it may be desirable torelieve the regular driver of his duties and permit 40 the commandingomcer in the turret to do the driving. Such would be desirable when thetank is being moved across country and is not under combat. Thecommanding officer in the turret can not only see whathe wants to do butcan do a his own driving which he is free to do as he does not have anycombat duties to perform. With the control system just described it isvery easy to so adapt it that it can also be operated by the commandingofllcer.

Referring again to Figure l, a second set of controls can be employed ina convenient place where the commanding officer in the turret de siresthese controls. These controls can be conduit 1 in order to obtain fluidpressure from the source and conduits 8 and 9 connect the.

valves to conduits 8 and 9. By operating the handles l6 and I8, theclutches can. be controlled in the same manner as when handles l6 and 18are controlled. However, before controlling the clutches by handles l6'and I8, it will be necessary to shut ofi the power cylinders 3 and 4from communication with the atmosphere through valve mechanism 5 Thiscan be accomplished by moving handles 16 and I8 forwardly to theirdotted line positions so that pas sages 25 are out of communication withthe cooperating ports 22 and 23.-

Also mounted on the control column 10 is a hand brake can be appliedregardless of whether mechanism 5. The conduit 1' is connected tocylinders and the atmosphere.

valve I! which is controlled by a handle 12. This valve may be of anytype such as, for example, the ordinary three-way valve. The valve isconnected to the source of pressure by a conduit is which is connectedinto conduit 7'. A second conduit 14 places the valve in communicationwith conduit 32 leading from the foot-operated control valve 29. Anexhaust connection is obtained through conduit 15. When handle '52 ismoved forwardly, it will shut off the exhaust conduit l and when it ismoved rearwardly tothe position shown, it will admit air-under pressurefrom the source to the brake operating power cylinder or cylinders,depending upon whether only one is in communication with conduit 32! orboth are in communication with conduit 32. In order that the exhaustport of the foot-operated valve 29 will not be in an open position whenthe commanding ofiicer desires to use the hand-operated valve H, thereis provided a shut-oil valve 16 for the exhaust conduit. ll of saidvalve 29. This shut-oil valve 16 is adapted to be controlled by treadlefill through a suitable linkage 18.

When treadle 30 is permitted to be released 'beyond its normallyreleased position, valve 16 will be closed. Thus when fluid pressure isadmitted to conduit 32 through valve II, it will not escape toatmosphere but will cause proper operation of the power cylinders 21 and28.

When the commanding oificer wants to return the control to the driver,all he need do is: to position the handles l2, l8 and I8 forwardly fromtheir upright positions. This will then cut off any communicationbetween the various power The column Ill c'anjthen be lowered so thatthe valves 5' and M will be out-of the way. (The driver can then controlthe clutches and brakes in the manner already described. It is thus seenthat the operation of the system can be shifted back and forth from thedriver to the commanding officer as desired.

Being aware of the possibility of modifications in the particularstructure herein described without departing from the fundamentalprinciples of my invention, I do not intend that its scope be limitedexcept as set forth by theappended claims.

Having fully described my invention, what I claim as new and .desire tosecure by Letters Patent of the United States is:

1. In fluid pressure control system for a vehicle having a driven memberon each side thereof and a brake associated with each member, a

fluid motor for applying each brake, a source of fluid pressuredifferent from atmosphere, conduit means between, the source of fluidpressure and each fluid motor, a main valve for placin the sourceof'fluid pressure in communication with the motors through the conduitmeans, andmeans for selectively causing either of the fluid motors tobe, cut off from communication with the source of fluidlpressure andplaced in communication with a body of fluid at atmospheric Qcommunicating with thefluid motor of the brake on one side of thevehicle and for placing said fluid motor in communication with a body offluid at atmospheric pressure, other valve means for preventing thesource of pressure from communicating with the fluid motor of the brakeon the other side of the vehicle and for placing said last named fluidmotor in communication witha body of fluid at atmospheric pressure, andmeans for selectively controlling said two last named valve means.

3. In a fluid pressure control system for a ve-, hicle having a drivenmember on each side thereof and a brake associated with each member, a

fluid motor for applying each brake, a source of fluid pressuredifierent from atmosphere, conduit means between the source of fluidpressure and each fluid motor, a main valve for placing the source offluid pressure-in communication motor closed and said other valve ofsaid motor source of fluid pressure and each of thefluid.

'motors, a valvefor placingeachfluid motor: in

with the motors through the conduit means, means for selectively causingeither of the fluid motors to be cut offirom communication with thesource of fluid pressure and placed in com--.

munication with a body of fluid at atmospheric pressure, and fluidpressure, operated means comprising an operator-operated control valvemeans for controlling said last named means at will.

4. In a fluid pressure control system for 2. vehicle having a drivenmember on each side there'- of and a brake associated with each member,a

fluid motor for applying each brake, a source of fluid pressuredifferent from atmosphere, conduit means between the source of fluidpressure and each fluid motor, valve mean for placing the source offluid pressure in communication with the motors through the conduitmeans, a valve for cutting ofi. communication between the source offluid pressure and eachof the fluid motors, a valve for placing eachfluid motor in communication with a body of fluid atatmospheric-pressure, a single member for-controlling said four lastnamed valves and normally maintaining said cut on" valves in openposition and the other valves in closed position, and means for movingsaid member in opposite directions 'from said normal position, saidmember when moved in one direction rendering the cut-01f valve of one.

fluid motor closed and the other valve of said motor open and when movedin the opposite direction rendering the cut-off valve of the other open.

5. In a fluid pressure controlsystem for a vehicle having a drivenmember on each'side thereof and a brake associated with each member, a

fluid motor for applying each brake, a source and each fluid motor,valve means for placing the source of fluid pressure in communicationWith the motors through the'conduit means, a valve for cutting oilcommunication between the communication with a body of fluid atatmospheric pressure, a single member for controlling said four lastnamed valves and normally maintaining said cut-01f valves in openposition and the other valves in closed position, and fluid pressureoperated means for selectively moving said.

member in opposite directions from said normal Position, said memberwhen moved in one direction rendering the cut-off valve of one fluid motor closed and the other valve of said motor open and when moved in theopposite direction render- 'ing the cut-ofl valve of the other motorclosed and said other valve of said motor open.

6. In a fluid pressure control system tor a vehicle having a drivenmember on each side thereof and a brake associated with each member, afluid motor for applying each brake, a source of fluid pressuredifierent from atmosphere, conduit means between the source of fluidpressure through the first named valve means when open and each fluidmotor, valve means for placing the source of fluid pressure incommunication with the motors through the conduit means, a

with .the fluid motor 01' the brake on the side of fluid motor forapplying each brake, a source valve for cutting 01! communicationbetween the source of fluid pressure and each of the fluid motors, avalve for placing each fluid motor in communication with a body of fluidat atmospheric pressure, a shaft provided with cams for controlling saidfour last named valves and normally maintaining said cut-off valves inopen of fluid pressure, conduit means between the source and each fluidmotor, independently operated valves for placing the source of fluidpressure in communication with the disconnecting motors, valve means forcontrolling the simultaneous connecting oi the source with both brakeposition and the other valves in closed position,

and means tor rotating said shaft in opposite directions from saidnormal position, said shaft when moved in one direction so controllingthe valves by the cards that the cut-ofi valve of one fluid motor willbe closed and'the other valve of said motor will be opened and whenmoved in the opposite direction the cut-off valve of the other motorwill be closed and the other valve of said 'motor will be opened.

7. In a fluid pressure control system for a vehicle having a drivenmember on each side thereof and a brake associated with each member, afluid motor for applying each brake, a source of fluid pressuredifferent from atmosphere, conduit means between the source of fluidpressure and I each fluid motor, valve means for placing the source offluid pressure in communication with the motors through the conduitmeans, a valve for cutting ofi communication between the source of fluidpressure and. each of the fluid motors, a valve for placing each fluidmotor in communication with a body of fluid at atmospheric pressure,

a single member for controlling said valves, means for normally biasingsaid member to a position where said cut-off valves will be in openposition and the other valves will be in closed position, a fluid motorhaving a movable element connected to movesaid member in oppositedirections from said normal position, said member when moved in onedirection from said normal position so controlling the cut-off valvesthat the cut-off valve of one brake fluid motor will be closed and theother valve of said brake motor will be open and when moved in theopposite direction the cut-off valve of the other brake motor will beclosed and the other valve of said brake motor will be open, andmanually-controlled valves for selectively admitting fluid pressure toopposite ofadapted to be disconnected from a source of power and anassociated brake for each member, ajluid motor for applying each brake,a source of fluid pressure, conduit means between the source of fluidpressure and each fluid motor, oporator-operated valve means forsimultaneously placing the source of fluid pressure in communifluidmotors, and means controlledby the operation of a disconnecting motor-onone 'side'ot the vehicle for cutting ofi communication between thesource and the fluid motor of the brake on the other side of the vehiclewhen the las named valve means is open. a

10. In a fluid pressure control system-for a vehicle having a drivenmember on each side there- 01 adapted to be disconnected from a sourceof power and an associated brake for each member, a fluid motor fordisconnecting each member, a

fluid motor for applying each brake, a source or fluid pressure, conduitmeans between the source and each fluid motor, independently operatedvalves. for placing the source of fluid pressure in communication withthe disconnecting motors, valve means for controlling the connecting ofthe source with both brake fluid motors, cut-oil valve means for eachbrake fluid motor, and means controlled by the fluid pressure employedto 0perate the disconnecting fluid motor on one side of the vehicle forclosing the cut-oil valve means of the brake fluid motor on the otherside of the vehicle.

11. In a fluid pressure control system for a vehicle having a drivenmember on each side, thereof adapted to be disconnected fro-ma source ofpower and an associated brake for each member, a source of fluidpressure, a fluid motor for disconnecting each memberfrom the source ofpower, valve means for selectively connecting each disconnecting fluidmotor to the source of fluid pressure, afluid motor for applying eachbrake, conduit means between the source and each brake fluid" motor,a'main valve for placing the source of pressure in communication withboth brake fluid motors, means operable by the employed to operate thefluid motor of the disconnecting means on the other side of the ve-'hicle for causing the fluidmotor of the brake on the opposite side ofthe vehicle to be cut oil from communication with the source of pressureand cation with both motors through the conduitq means, means forindependentlydisconnecting the driven members from the source of power,

's0l1l'0e of fluid pressure from communicating placed in communicationwith the atmosphere.

of, adapted to be disconnected from a source of power and an associatedbrake for each member,

' I a source of fluid pressure, a fluid motor for disconnectingeachmember from the source of power, valve means for selectivelyconnecting each disconnecting fluid motor to the, source of -fluidpressure, a fluid motor for applying'each brake, conduit means betweenthe source and each brake fluid motor, a main valve for placingthe'source of pressure in communication with both brake fluid motors,valve means for preventing the source of pressure from communicatingwith the fluid motor of the brake on one side of the vehicle and forplacing said fluid motor in communication with atmosphere, other valvemeans for preventing the source of pressure from communicating with thefluid motor of the brake on the other side of the vehicle and forplacing said last named fluid motor in communication with atmosphere,and fluid pressureoperated means for controlling said two last namedvalve means, said fluid pressure-operated means being connected to thefluid pressure means of the disconnecting fluid motors in such a mannerthat when the member on one side of the vehicle is disconnected saidfluid pressureoperated means will cause the valve means for the fluidmotor of the brake on the opposite side of the vehicle to be operated.

13. In a fluid pressure control system for a vehicle having a drivenmember on each side thereof adapted to be disconnected from a source ofpower and an associated brake for each member, a source of fluidpressure, a fluid motor for disconnecting each member from the source ofpower, valve means for selectively connecting each disconnecting fluidmotor to the source of fluid,

off valves in open position and the other valves in closed position,meansfor so moving said single member byrthe fluid pressure establishedto operate the disconnecting fluid motor on one side of the vehicle thatthe two valves associated with the brake fluid motor on the oppositeside of the vehicle will be operated to cut off said brake fluid motorfrom the source of fluid pressure and place it in communication withatmosphere, and means for so moving said single member by the fluidpressure established to operate the disconnecting fluid motor on theother side of the vehicle that the two valves associated with the brakefluid motor on the opposite side of the vehicle will be operated to-cutoff said brake fluid motor from the source of fluid pressure and placeit in communication with atmosphere.

14. Ina fluid pressure control system fora vehicle having a drivenmember on each side thereof adapted to be disconnected from a source ofpower and an associated brake for each mempressure in communication withboth brake applying fluid motors,one setof the separate valves for thedisconnecting motors and a valve for the brake fluid motors beinggrouped together and remotely positioned from the other set of separatevalves for the disconnecting motors and the other valve for the brakeoperating fluid motors so that an operator may control the disconnectingand brake applying motors from either of two remote positions, and meanscontrolled by the operation of the disconnecting motor on one side ofthe vehicle for cutting ofl communication between thesource of fluidpressure and the fluid motor of the brake on the other side of thevehicle.

15. In a fluid pressure control system for a vehicle having a drivenmember on each side thereof adapted to be disconnected from a source ofpower and an associated brake for each memher, a source of fluidpressure, a fluid motor for disconnecting each member, means comprisinga v set of separate hand-operated valves for controlling communicationbetween the source of fluid pressure and the disconnecting fluid motors,other means comprising a second set of separate hand-operated valves foralso controlling communication between the source of fluid pressure andthe disconnecting fluid, motors, means comprising a foot-operated valvefor placing the source of fluid pressure in communication with bothbrake applying fluid motors, means comprising a hand-operated valve foralso placing the source of fluid pressure in communication with bothbrake applying fluid motors, one set of the separate valves for thedisconnecting motors and the foot-operated valve for the brake fluidmotors being so positioned that they can all be controlled by anoperator and the other set of separate valves for the disconnectingmotors and the hand-operated valve for the brake fluid motors beinggrouped together and positioned remotely from the other valves so as tobe operable by an operator at said remote position, and means controlledby the operation of the disconnecting motor on one side of the vehiclefor cutting off communication between the source of fluid pres-- sureand the fluid motor of the brake on the other side of the vehicle.

WERNER FL. BOLDT.

